Pipes have long been used for the delivery of various fluids, and the methods used for their installation are well-established. While the following invention can apply to many types of pipe for the delivery of many types of fluid, the following discussion will be focused upon liquid delivery, namely water pipes. Typically, water mains employ a type of pipe known as ductile iron. Lengths of pipe are coupled by inserting the end of one pipe into a belled end of an adjacent pipe. Using uncut lengths of pipe, this system works quite efficiently. However, problems develop when a length of pipe must be shortened by cutting. The cut end of the pipe has a relatively sharp edge which when inserted into the belled end of the adjacent pipe may damage the gasket located therein. This is typically referred to as “fish mouthing”, and results in leakage at the joint.
Conventionally, this problem is overcome by cutting a bevel into the cut pipe end. This, however, creates more problems. Specifically, forming a bevel in ductile iron pipe is extremely difficult. Currently, the bevel is formed using the cut-off saw previously used to cut the pipe to the desired length. The saw used is cumbersome and heavy, has a blade turning at approximately 5600 rpms, and is therefore dangerous and imprecise. Furthermore, the blade manufacturers specifically prohibit this use of the blade, because the stresses are uneven and shattering of the blade tends to occur. As well as being dangerous, forming a bevel in this manner is expensive due to the time in labor and increased number of blades used.
Beveled attachments have been developed for aiding in the insertion of an end of a pipe segment through a gasket in a belled end of a pipe segment. While very effective, placing a beveled attachment on the end of a pipe segment and inserting the pipe can require some practice. When done properly, beveled attachments work extremely well, but, as with many things, improperly positioned attachments may work improperly.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved method and apparatus for facilitating the coupling of pipes.
Another object of the invention is to provide a beveled insert, which permits insertion of a pipe end without damaging a sealing gasket.
And another object of the invention is to provide a device in the belled end of a pipe segment already prepared for the insertion of a pipe end.
Yet another object of the present invention is to provide a beveled insert capable of electrically disconnecting pipe segments or if desired, electrical coupling pipe segments.